Grasper with magnetically-controlled positioning

ABSTRACT

Described here are devices, systems, and methods for providing remote traction to tissue. Generally, the systems may include a grasper and a delivery device configured to releasably couple to the grasper. The grasper may have a first jaw and a second jaw and a main body having a barrel portion. The barrel portion may have a lumen extending therethrough, and a portion of the delivery device may be advanced through the lumen to rotate one or both of the jaws. The delivery devices may include a handle, a shaft, and a distal engagement portion. The delivery devices may further include an actuation rod which may be advanced through a barrel portion of a grasper to actuate the grasper. In some instances, the delivery device may further include a locking sheath, wherein the locking sheath is configured to temporarily couple to a grasper.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 61/778,264, filed on Mar. 12, 2013, which is hereby incorporated byreference in its entirety.

FIELD

The present invention is directed toward systems, devices, and methodsfor providing remote manipulation or traction to tissue using one ormore graspers.

BACKGROUND

Many surgical procedures are shifting toward the use ofminimally-invasive approaches that are configured to minimize the numberand size of incisions that are made in a patient. Minimally-invasiveprocedures such as endoscopic and laparoscopic procedures may beassociated with lower pain, quicker post-surgical recovery, shortenedhospitalization, and reduced complications when compared to opensurgical procedures. During minimally-invasive procedures it may bedesirable to reposition or otherwise manipulate tissue, however theintroduction of additional devices to engage tissue may crowd the accesssites provided by incisions, which may require the formation of largeror additional access sites. Accordingly, it may be desirable to provideone or more devices that may retract or otherwise manipulate tissuewithout the need to have a portion of the device present in an accesssite to the body.

BRIEF SUMMARY

Described here are devices, systems, and methods for providing remotetraction for tissue. In some variations, the systems described here maycomprise a grasping device. The grasping device may comprise a main bodycomprising a barrel portion having a lumen extending therethrough, afirst jaw rotatably coupled to the main body, and a second jaw. Thegrasper may further comprise a proximal arm extending from the firstjaw, wherein at least a portion of the proximal arm is exposed from themain body. The device may be configured such that a one or more forces(e.g., a compressive force or the like) applied to the exposed portionof the proximal arm and the main body rotates the first jaw relative tothe second jaw. Additionally or alternatively, the device may beconfigured such that advancement of an actuation rod through the lumenof the barrel portion rotates the first jaw relative to the second jaw.

In some variations, the lumen of the barrel portion may comprise aproximal segment and distal segment such that a diameter of the proximalsegment is larger than a diameter of the distal segment. In some ofthese variations, the lumen may further comprise an intermediate segmentbetween the proximal segment and the distal segment such that a diameterof the intermediate segment is larger than the diameter of the proximalsegment and the diameter of the distal segment. At least a portion ofthe device may be formed from one or more magnetic or ferromagneticmaterials. In some variations, the device may further comprise aneccentric cam member attached to the first jaw such that rotation of theeccentric cam member is configured to rotate the first jaw. The proximalarm may comprise a curved segment. In some of these variations, theproximal arm may further comprise a straight segment positioned betweenthe curved segment and the first jaw. The first jaw may be rotationallybiased toward the second jaw.

Also described here are systems for grasping tissue. The system maycomprise a grasper and a delivery device. The grasper may comprise amain body comprising a barrel portion having a lumen extendingtherethrough, a first jaw rotatably coupled to the main body, and asecond jaw. The grasper may comprise a proximal arm connected to thefirst jaw, such that rotation of the proximal arm relative to main bodyrotates the first jaw away from the second jaw. In some variations, thegrasper may further comprise an eccentric cam member attached to thefirst jaw, wherein rotation of the eccentric cam member is configured torotate the first jaw. In some of these variations, the proximal arm maycomprise a curved segment, and in some of these variations may comprisea straight segment positioned between the curved segment and the firstjaw.

The delivery devices described here may comprise a handle, a distalengagement portion configured to releasably couple to the grasper, ashaft connecting the handle and the distal engagement portion, and anactuation rod. The actuation rod may be advanced through the lumen torotate the first jaw away from the second jaw. In some variations, thedelivery device comprises a locking sheath having an expandable distalend. The delivery device may be configured to expand the expandabledistal portion from an unexpanded configuration to an expandedconfiguration in the lumen of the barrel portion to couple the lockingsheath to the grasper. In some of these variations, the lumen of thebarrel portion may comprise a proximal segment and distal segment,wherein a diameter of the proximal segment is larger than a diameter ofthe distal segment. The expandable distal portion of the locking sheathmay be advanced through the proximal segment in an unexpandedconfiguration and may be prevented from being advanced through theproximal segment when in the unexpanded configuration.

In some of these variations, the lumen may further comprise anintermediate segment between the proximal segment and the distalsegment, wherein a diameter of the intermediate segment is larger thanthe diameter of the proximal segment and the diameter of the distalsegment. The expandable distal portion of the locking sheath may beconfigured to be expanded in the intermediate section, such that theexpandable distal portion of the locking sheath is prevented from beingwithdrawn through the proximal segment when the expandable distalportion of the locking sheath is expanded. The actuation rod may bepositioned within the locking sheath, and may be configured such thatadvancement of the actuation rod relative to the locking sheath expandsthe expandable distal portion of the locking sheath. In some of thesevariations, the expandable distal portion of the locking sheath maycomprise at least one internal projection configured to fit in at leaston indentation of the actuation rod. Advancement of the actuation rodrelative to the locking sheath may slide the at least one internalprojection relative to the at least one indentation to expand theexpandable distal portion of the locking sheath.

In some variations, the distal engagement portion of the delivery devicemay comprise a coupling magnet. In some of these variations, retractionof the coupling magnet may decouple the grasper from the distalengagement portion. The retraction of the actuation rod may beconfigured to retract the coupling magnet. In some variations, thedistal engagement portion may comprise a spring (e.g., a torsionalspring, a cantilever spring, or the like) positioned to bias thecoupling magnet toward an advanced position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C depict perspective views of an illustrative variation of thesystems described here.

FIGS. 2A-2F depict cross-sectional side views of a distal portion of avariation of the delivery devices described here and a variation of thegraspers described here.

FIGS. 3A, 3B, 4A, and 4B depict cross-sectional side views ofillustrative variations of the graspers described here.

FIGS. 5A-5D depict a variation of the methods described here.

FIGS. 6A and 6B show perspective and side views, respectively, of avariation of a grasper as described here. FIG. 6C shows across-sectional side view of the grasper of FIGS. 6A and 6B.

FIGS. 7A-7D depict cross-sectional side views of a distal portion of avariation of the delivery devices described here and the grasper ofFIGS. 6A and 6B.

DETAILED DESCRIPTION

Described here are devices, systems, and methods for providing remotesuspension/traction or manipulation of tissue during minimally-invasiveprocedures. Generally, the systems described here include a grasper thatis configured to be releasably connected to tissue. The grasper may befurther configured to be attracted to one or more magnets positionedexternally of the body to move, reposition, and/or hold the grasper(which may in turn provide traction for the tissue held by the grasper).The systems described here may also comprise a delivery device. Thedelivery devices described here are generally configured to releasablycarry the grasper, and may be further configured to actuate the grasperto selectively connect the grasper to tissue or release the grasper fromtissue. The delivery devices are typically further configured to releasethe grasper from the delivery device (e.g., after the grasper has beenconnected to tissue). In some instances, the delivery may be configuredto re-couple to the grasper to reposition or remove the grasper. Inother instances the system may comprise a separate retrieval deviceconfigured to reposition or remove the grasper. In some instances, thedelivery device or retrieval device may be used with the grasper toremove tissue from the body. For example, the grasper may be connectedto a tissue such as the gall bladder, the tissue may be severed from thebody (e.g., using one or more surgical tools), and the grasper may beretrieved using the delivery device or another retrieval device toremove the grasper and tissue from the body.

In some variations, the system may further comprise a magnetic controlelement (which may include one or more magnets), which may be configuredto be positioned outside the body and to provide a magnetic force to thegrasper when the grasper is positioned in the body (e.g., to move,reposition, and/or hold the grasper). While illustrative examples of thegraspers and delivery devices are described together below, it should beappreciated that any of the graspers described here may be used with anyof the delivery devices described here. It should be appreciated thatthe graspers described here may be actuated and delivered using anysuitable delivery device, and that that the delivery devices describedhere may be used to actuate and deliver any suitable grasper or graspingdevice.

Generally, the methods described here comprise releasably connecting agrasper (such as one of the graspers described here) to a tissue, andproviding a magnetic force to the grasper to move and/or hold thegrasper and provide traction of the tissue engaged by the grasper. Themagnetic force may be provided by a magnetic control element configuredto magnetically attract the grasper. In some variations, the grasper maybe releasably connected to a tissue inside of the body, and the magneticcontrol element may be positioned externally of the body to magneticallyattract the grasper. To connect the grasper to the tissue, the graspermay be releasably coupled with a delivery device, wherein the deliverydevice is configured to actuate the grasper. The delivery device mayactuate the grasper to releasably connect the grasper to tissue, and mayeject or otherwise decouple from the grasper after the grasper isconnected to tissue. When the grasper is decoupled from the deliverydevice, the grasper may be attracted by an magnetic force external tothe body and may move or otherwise hold tissue without the need to havea shaft or other portion of a device positioned in a laparoscopic portor other access site. This may reduce the number of access sitesrequired to provide remote suspension of tissue, which may allow forfaster and more reliable surgical procedures. In some instances, thedelivery device (or another device, such as a grasping device) may beused to disconnect the grasper from tissue. The grasper may then berepositioned and reattached to tissue (either the same tissue or adifferent tissue), or may be removed from the body.

FIGS. 1A-1C depict one variation of the systems described here.Specifically, FIG. 1A shows a perspective view of a system comprising adelivery device (100) and a grasper (200). The grasper may be releasablycoupled to the delivery device (100) (as shown in FIGS. 1A and 1B), andmay be decoupled from the delivery device (as shown in FIG. 1C). Whenthe grasper (200) is coupled to the delivery device (100), the deliverydevice (100) may actuate the grasper to connect the grasper to tissue orrelease the grasper therefrom.

As shown in FIG. 1A, the delivery device (100) may comprise a handle(104), a shaft (106) extending from the handle (104), and a distalengagement portion (108) at a distal end of the shaft (106). In somevariations, the delivery device (100) and grasper (200) may beconfigured for laparoscopic introduction into the body. Accordingly, insome variations the grasper (200) and delivery device (100) may beconfigured for advancement through a 10 mm laparoscopic port. In thesevariations, the outer diameter of the grasper may be less than or equalto about 10 mm. Additionally, the delivery device (100) may beconfigured such that the shaft (106) and the distal engagement portion(108) each have a diameter of less than or equal to about 10 mm. In someof these variations, the distal engagement portion (108) may have anouter diameter of less than or equal to about 10 mm, while the shaft(106) has an outer diameter of less than or equal to about 5 mm. Inthese variations, it may be possible to advance the distal engagementportion (108) through a 10 mm laparoscopic port, and to further advancea second device having a diameter of about 5 mm or less through the portwhile the shaft (106) is positioned in the port. It should beappreciated that shaft (106) may have any suitable diameter (e.g.,between about 1 mm and about 15 mm, between about 5 mm and about 10 mm,or the like). The shaft (106) and distal engagement portion (108) may beformed from any suitable materials, such as one or more medical-grade,high-strength plastics or metals, such as stainless steel, cobaltchromium, PEEK, one or more nylons, polyimide, or the like.

Generally, the handle (104) comprises an actuation control mechanismthat may be manipulated by a user to controllably actuate the grasper.In some variations, the delivery device may comprise a separatedecoupling control, which a user may use to decouple the grasper (200)from the delivery device (100). In other variations, the delivery device(100) may be configured such that a user may use the actuation controlmechanism to decouple the grasper from the delivery device in additionto actuating the grasper. For example, in the variation of the deliverydevice (100) depicted in FIGS. 1A-1C, the handle (104) of deliverydevice (100) may comprise a grip portion (110) and an actuation controlmechanism comprising a trigger (112). While shown in FIGS. 1A-1C asbeing a trigger (112), it should be appreciated that the actuationcontrol mechanism may comprise any suitable control element (e.g., aslider, a knob, or the like) capable of actuating the grasper (200) asdescribed in more detail below. The trigger (112) may be configured toboth actuate the grasper (200) and decouple the grasper (200) from thedelivery device (100).

Specifically, in some variations the trigger (112) may be moveablebetween three positions. While three distinct positions will bediscussed below, it should be appreciated that the trigger (112) mayalso assume one or more intermediate positions between these positions.Of the three positions, the trigger may be moveable between a firstposition (as shown in FIG. 1A) and a second position (as shown in FIG.1B) to actuate the grasper (200). Specifically, the grasper (200) maycomprise a first jaw (202) and a second jaw (204), and at least one ofthe first jaw (202) and the second jaw (204) may be configured to rotaterelative to the grasper (200). The grasper (200) may be actuated betweenan open configuration and a closed configuration.

In the open configuration, the first jaw (202) and second jaw (204) maybe held in rotationally separated positions to define a space betweenthe first jaw (202) and the second jaw (204), as shown in FIG. 1B. Inthe closed configuration, the first jaw (202) and second jaw (204) maybe rotationally biased toward each other, as shown in FIG. 1A. While thefirst jaw (202) is shown in FIG. 1B as contacting the second jaw (204)when the grasper (200) is in the closed configuration, it should beappreciated that when the grasper (200) is connected to tissue, tissuepositioned between the first jaw (202) and second jaw (204) may preventthe first jaw (202) from contacting the second jaw (204) when thegrasper (200) is in the closed configuration.

The grasper (200) may be actuated between the closed and openconfigurations to releasably connect the grasper (200) to tissue. Forexample, when the trigger (112) is in the first position (as shown inFIG. 1A), the grasper (200) may be placed in the closed configuration.As the trigger (112) is moved to the second position (as shown in FIG.1B), the grasper (200) may be moved to the open configuration. Invariations where the first jaw (202) is configured to rotate relative tothe grasper (200), moving the trigger (112) from the first position tothe second position may rotate the first jaw (202) away from the secondjaw (204), while moving the trigger from the second position back to thefirst position may rotate the first jaw (202) toward the second jaw(204). Accordingly, by moving the trigger (112) between the first andsecond positions, a user may selectively open and close the jaws of thegrasper (200) using the delivery device (100). To connect the grasper(200) to tissue, a user may place the trigger (112) in the secondposition (or an intermediate position between the first and secondpositions) to open (or partially open) the jaws, and may manipulate thedelivery device (100) to position tissue between the first jaw (202) andthe second jaw (204). With the tissue positioned between the jaws, thetrigger (112) may be returned to the first position to clamp the jawsagainst the tissue, thereby releasably connecting the grasper (200) tothe tissue.

As mentioned above, the trigger (112) may be configured to decouple thegrasper (200) from the delivery device. For example, the trigger (112)may be moved from the first position (as shown in FIG. 1A) to a thirdposition (as shown in FIG. 1C), and the delivery device (100) may beconfigured to decouple from the grasping member when the trigger ismoved to the third position (as will be described in more detail below).When the same actuation control mechanism is used to actuate the grasperand decouple the grasper from the delivery device, it may be desirableto decouple the grasper from the delivery device when the grasper (200)is in a closed configuration and engaged with tissue. Accordingly, insome variations, the first position of the trigger (112) (which maycorrespond to a closed configuration of the grasper (200)) may be anintermediate position between the second position and third position. Inthese variations, when the trigger (112) is placed in the secondposition to place the grasper (200) in an open configuration, thetrigger (112) will move through the first position (which may move thegrasper (200) to a closed configuration) before it reaches the thirdposition. Thus the grasper (200) may be moved to the closedconfiguration before it is decoupled from the delivery device (100).

The delivery devices described here may be configured to actuate, coupleto, and decouple from, the graspers described here in any suitablemanner. For example, FIGS. 2A-2F illustrate one suitable mechanism bywhich a delivery device may be configured to actuate and couple/decouplea grasper. For example, FIG. 2A depicts a cross-sectional side view ofvariations of the grasper (200) and a distal portion of the deliverydevice (100) each described above with respect to FIGS. 1A-1C. As shownthere, the grasper (200) may comprise a first jaw (202), a second jaw(204), and a main body (206). Generally, the first jaw (202) isrotatably connected to the main body (206) at a pivot point (208), suchthat the first jaw (202) may rotate relative to the main body (206). Insome variations (such as that shown in FIGS. 2A-2F), the second jaw(204) may be fixed relative to the main body (206), while in othervariations the second jaw (204) may also be rotatably connected to themain body (206). When the second jaw (204) is fixed relative to the mainbody, the second jaw (204) may be formed separately from the main body(206) and subsequently attached thereto, or may be formed integrallywith the main body (206). When a jaw as described here is configured torotate relative a pivot point, the jaw may be configured to rotate inany suitable manner. In some variations, a jaw may be connected to themain body via a rotation pin, such that the jaw may rotate around therotation pin (or the jaw and rotation pin may rotate relative the mainbody). In other variations, the jaw may be connected to the main bodyvia a living hinge.

The first jaw (202) and second jaw (204) may be rotationally biasedtoward each other (e.g., towards a closed configuration). In variationswhere the first jaw (202) is rotatably connected to the main body, thefirst jaw (202) may be rotationally biased toward the second jaw (204).For example, in some variations the grasper (200) may comprise a springsuch as a torsional spring or a cantilever spring (not shown), which mayspring-bias the first jaw (202) toward the second jaw (204). Invariations where the second jaw (204) is rotatably connected to the mainbody, the second jaw (204) may also be biased towards the first jaw(202) (e.g., via one or more springs). The bias of the jaws toward theclosed configuration may act to hold tissue positioned between the firstjaw (202) and the second jaw (204).

As shown in FIG. 2A, the main body (206) of the grasper may comprise abarrel portion (210) with a lumen (212) extending therethrough. Aportion of the delivery device (100) may be advanced through the lumen(212) to rotate first jaw (202) (and in some instances, the second jaw(204) in variations where the second jaw (204) is rotatably connected tothe main body (206)) relative to the main body (206), as will bedescribed in more detail below. In some variations, the lumen (212) mayhave a constant diameter. In other variations, different portions of thelumen (212) may have different diameters.

For example, in the variation of the grasper (200) shown in FIGS. 2A-2F,the lumen (212) of the barrel portion (210) may comprise a proximalsegment (214), a distal segment (216), and an intermediate segment (218)positioned between the proximal segment (214) and the distal segment(216). As shown in FIG. 2A, the proximal segment (214) may have a largerdiameter than the distal segment (216), and the intermediate segment(218) may have a larger diameter than both the proximal segment (214)and the distal segment (216). The proximal (214), distal (216), andintermediate (218) segments may aid in maintaining a coupling with thedelivery device (100), as will be described in more detail below.

The barrel portion (210) of the grasper (200) may be sized andconfigured to be engaged by the distal engagement portion (108) of thedelivery device (100) to releasably couple the grasper (200) to thedelivery device (100). In some variations, the outer diameter of thebarrel portion (210) may have a constant diameter, or may have differentportions of the barrel portion (210) having different diameters, such asdescribed in more detail below. Turning to the delivery device (100), inthe variation of the delivery device shown in FIGS. 2A-2F, the deliverydevice (100) may comprise an actuation rod (114) slidably disposed inthe shaft (106). The actuation rod (114) may be advanced through thelumen (212) of the barrel portion (210) of the grasper (200) to actuatethe grasper (200), as will be described in more detail below. Also shownin FIG. 2A is a locking sheath (116), a coupling magnet (118), and aspring (120). Each of these components will be discussed further below.

While shown in FIGS. 2A-2F as having a coupling magnet (118), thedelivery device (100) need not comprise a coupling magnet. In variationsof the delivery device (100) that do comprise a coupling magnet (118),the coupling magnet (118) may be slidably housed in a housing of thedistal engagement portion (108), and may be configured to releasablycouple the delivery device (100) to the grasper (200). The couplingmagnet (118) may be movable between an advanced position (as depicted inFIG. 2A) and a retracted position (as depicted in FIG. 2C). Invariations where the delivery device comprises a spring (120), thespring (120) may be positioned in the distal engagement portion (108) tobias the coupling magnet (118) toward the advanced position.

The delivery device (100) may be configured to couple to the grasper(200) when the coupling magnet (118) is in the advanced position. Forexample, when the distal engagement portion (108) is brought near thegrasper (200), the coupling magnet (118) may attract the grasper (200).Generally, at least a portion of the graspers described here are formedfrom one or more metallic or magnetic materials which may be attractedto a magnetic field. The materials may include one or more magnetic orferromagnetic materials, such as, for example, stainless steel, iron,cobalt, nickel, neodymium iron boron, samarium cobalt, alnico, ceramicferrite, alloys thereof and/or combinations thereof. Accordingly, one ormore portions of the grasper (200) may be formed from or otherwiseinclude a magnetic or ferromagnetic material, such that it may beattracted to a magnetic field produced by the coupling magnet (118). Theattractive force provided by the coupling magnet (118) may hold thegrasper (200) against or at least partially within the distal engagementportion (108), such as shown in FIG. 2B. The grasper (200) may bepositioned such that a proximal end of the barrel portion (210) of thegrasper is held against or at least partially within the distalengagement portion (108) of the delivery device (100).

To decouple the grasper (200) from the distal engagement portion (108),the coupling magnet (118) may be withdrawn to the retracted position, asshown in FIG. 2C. Because the force applied by a magnet decreases as afunction of the distance from the magnet, moving the coupling magnet(118) to the retracted position may increase the distance between thegrasper (200) and the coupling magnet (118) (e.g., the distal engagementportion (108) may comprise a stop (121) which may prevent the grasperfrom being retracted with the coupling magnet (118)), which may reducethe attractive force felt by the grasper (200). Eventually, theattractive force may be sufficiently diminished such that the grasper(200) may decouple from the delivery device (100).

The coupling magnet (118) may be retracted in any suitable manner. Insome variations, the delivery device (100) may comprise a control sheath(not shown) which may be attached to the coupling magnet (118). Thecontrol sheath may be selectively withdrawn or advanced (e.g., via acontrol mechanism in the handle (104)) to withdraw and advance,respectively, the coupling magnet (118). In other variations, a portionof the actuation rod (114) may be configured to retract the couplingmagnet (118). For example, the actuation rod (114) may be configured tocatch on or otherwise engage the coupling magnet (118) during retractionof the actuation rod (114). In these variations, the actuation rod (114)may be withdrawn until the actuation rod (114) engages the couplingmagnet (118). Once the actuation rod (114) engages the coupling magnet(118), further withdrawal of the actuation rod (114) may also withdrawthe coupling magnet (118).

For example, as shown in FIGS. 2A-2F, the actuation rod (114) may beslidably disposed within a lumen (122) of the coupling magnet (118). Insome variations, at least a segment of the actuation rod (114) may besized and configured such that the portion of the actuation rod (114)cannot fully pass through the lumen (122). For example, in somevariations a segment of the actuation rod may have a diameter greaterthan a diameter of the lumen (122). Additionally or alternatively, thesegment may comprise one or more projections extending from an outersurface of the actuation rod (114) and which cannot fully pass throughthe lumen (122). When the segment of the actuation rod (114) ispositioned distal to the coupling magnet (118), the actuation rod (114)may be freely advanced relative to the coupling magnet (118).Conversely, withdrawal of the actuation rod (114) may pull the segmentof the actuation rod (114) into contact with the coupling magnet (118).Since the segment cannot fully pass through the lumen (122) of thecoupling magnet (118), further withdrawal of the actuation rod (114) maycause the segment of the actuation rod (114) to pull on and withdraw thecoupling magnet (118). When the actuation rod (114) is subsequentlyadvanced, the spring (120) may advance the coupling magnet (118) withthe actuation rod (114) until the coupling magnet (118) reaches theadvanced position.

In variations where the delivery device (100) comprises a locking sheath(116) slidably disposed in the lumen (122) of the coupling magnet (118),the locking sheath (116) may be configured to withdraw the couplingmagnet (118). For example, a segment of the locking sheath (116) may besized and configured such that the segment cannot fully pass through thelumen (122) of the coupling magnet (118), such as described above withrespect to the actuation rod (114). In the variation shown in FIGS.2A-2F, the locking sheath (116) may comprise a protrusion (124)positioned distally of the coupling magnet (118) and sized such that theprotrusion (124) cannot fully pass through the lumen (122). In thesevariations, proximal withdrawal of the locking sheath (116) through thelumen (122) may place the protrusion (124) into contact with thecoupling magnet (118), such as shown in FIGS. 2A and 2B. As depicted inFIG. 2C, further withdrawal of the locking sheath (116) may alsowithdraw the coupling magnet (118) (e.g., by virtue of the contactbetween the protrusion (124) and the coupling magnet (118)).

As mentioned above, the delivery devices described here may comprise alocking sheath (although it should be appreciated that in somevariations the delivery device may not comprise a locking sheath). Invariations where the delivery device does comprise a locking sheath(116), such as the variation of the delivery device (100) depicted inFIGS. 2A-2F, the locking sheath (116) may be slidably disposed in theshaft (106). The actuation rod (114) may in turn be positioned at leastpartially within the locking sheath (116). The locking sheath (116) maycomprise an expandable distal portion (126) which may be configured toexpand inside of the lumen (212) of the barrel portion (210) of thegrasper (200) to temporarily engage an interior portion of the lumen(212), which may help maintain the coupling between the grasper (200)and the delivery device (100).

In these variations, the delivery device (100) may be configured suchthat advancement of the actuation rod (114) relative to the lockingsheath (116) may expand the expandable distal portion (126) of thelocking sheath (116). For example, the expandable distal portion (126)of the locking sheath (116) may comprise at least one internalprojection (128) that projects inwardly and is sized and shaped to fitwithin at least one corresponding indentation (130) in the outer surfaceof the actuation rod (114). It should be appreciated that the at leastone internal projection (128) may be a single projection (e.g., anannular snap-fit or a projection that extends radially around some orall of the inner circumference of the locking sheath (116)) or multiplediscrete projections. Similarly, the actuation rod (114) may comprise asingle indentation (e.g., an indentation that extends radially aroundsome or all of the outer surface of actuation rod (114)) or multipleindentations.

The actuation rod (114) may be positioned within the locking sheath(116) such that the internal projections (128) of the locking sheath(116) are positioned in corresponding indentations (130) of theactuation rod (114), such as shown in FIGS. 2A-2D. This may create afriction fit or mechanical interlock between the actuation rod (114) andthe locking sheath (116), which may cause the locking sheath (116) to beadvanced and withdrawn with the actuation rod (114). The engagementbetween the actuation rod (114) and the locking sheath (116) may befurther configured such that under certain circumstances the actuationrod (114) may be advanced relative to the locking sheath (116) to expandthe expandable distal portion (126) of the locking sheath (116). Forexample, as shown in FIGS. 2A-2F, the internal projections (128) of thelocking sheath (116) and the corresponding indentations (130) of theactuation rod (114) may each have a ramped proximal portion. When theinternal projections (128) are positioned within correspondingindentations (130), the ramped proximal portion of each internalprojection (128) may be positioned in contact with the ramped proximalportion of a corresponding indentation (130). This contact may providethe friction fit or mechanical interlock that may allow the actuationrod (114) to distally advance the locking sheath (116) as mentionedabove.

When an external force is applied to the locking sheath (116) to resistdistal advancement of the locking sheath (116), advancement of theactuation rod (114) may overcome the friction force or mechanicalconnection between the ramped proximal portions of the internalprojections (128) and the corresponding indentations (130), at whichpoint the contacting ramped surfaces may slide relative to each other asthe actuation rod (114) begins to advance distally relative to thelocking sheath (116). As the actuation rod (114) is advanced distallyrelative to the locking sheath (116), the internal projections (128) mayslide out of their corresponding indentations (130) (such as shown inFIG. 2E), which may thereby expand the expandable distal portion (126)of the locking sheath (116).

This expansion of the expandable distal portion (126) of the lockingsheath (116) may help to maintain the temporary coupling between thedelivery device (100) and the grasper (202), as illustrated in FIGS.2D-2F. Specifically, the locking sheath (116) and actuation rod (114)may be positioned such that the internal projections (128) of thelocking sheath (116) are positioned in respective indentations (130) onthe actuation rod (114), which may allow advancement and retraction ofthe actuation rod (114) to advance and retract the locking sheath (116),as discussed above. The grasper (200) may be coupled to the distalengagement portion (108) of the delivery device (100), as shown in FIG.2C, and the actuation rod (114) may be advanced to begin advancing theactuation rod (114) and locking sheath (116) into the lumen (212) of thebarrel portion (210) of the grasper (200). The actuation rod (114) maybe sized such that it is smaller than each of the proximal segment(214), the distal segment (216), and the intermediate segment (218) ofthe lumen (212) of the barrel portion (210) of the grasper (200). Thismay allow the actuation rod (114) to be advanced through the entirelumen (212) of the barrel portion. The locking sheath (116), however,may be sized and configured such that it may pass through the proximalsegment (214) and the intermediate segment (218) of the lumen (212), butis prevented from entering the distal segment (216). Accordingly, theactuation rod (114) may be advanced to advance the actuation rod (114)and the locking sheath (116) through the lumen (212) of the barrelportion (210) of the grasper (200) until the locking sheath (116)reaches the distal segment (216) of the lumen (212), as shown in FIG.2D. At this point, the locking sheath (116) may be prevented fromentering the distal segment (216), and may thus be prevented fromfurther advancement. The actuation rod (114) may be further advancedrelative to the grasper (200) to advance the actuation rod (114) throughthe distal segment (216) of the lumen (212). Because the locking sheath(116) is prevented from advancing further, the actuation rod (114) maybe advanced relative to the locking sheath (116). This may cause theinternal projections (128) of the locking sheath (116) to slide out oftheir respective indentations (130) and expand the expandable distalportion (126) of the locking sheath (116), as depicted in FIG. 2E.Specifically, the expandable distal portion (126) may be positioned inthe intermediate segment (118) of the lumen (112) when it is expanded.

When expanded, the expandable distal portion (126) may be configured toresist being removed from the lumen (212) of the barrel portion (210) ofthe grasper (200). Specifically, the expandable distal portion (126) ofthe locking sheath (116) may be sized and configured such that, whenexpanded, the expandable distal portion (126) may be prevented frompassing through the proximal segment (214) of the lumen (212) (e.g., theouter diameter of the expanded distal portion (126) may be larger thanthe diameter of the proximal segment (214) of the lumen (212)). When theexpandable distal portion (126) of the locking sheath (116) is expandedin the intermediate segment (218) (as shown in FIG. 2E), the lockingsheath (116) may resist both advancement of the locking sheath (116)into the distal segment (216) (as discussed above) and withdrawal of thelocking sheath (116) though the proximal segment (214) of the lumen(212). Accordingly, the expanded locking sheath (116) may lock thegrasper (200) in place relative to the delivery device (100). When theactuation rod (114) is further advanced to actuate the jaws of thegrasper (as shown in FIG. 2F, and discussed in more detail below), theactuation rod (114) may apply one or more forces to the grasper (200)which may have a tendency to push the grasper (200) away from thecoupling magnet (118) (which in some instances could possiblyinadvertently decouple the grasper (200) from the delivery device(100)), but the engagement between the expanded locking sheath (116) andthe grasper (200) may overcome these forces to maintain the position ofthe grasper (200) relative to the delivery device (100).

To disengage the locking sheath (116) from the grasper (200), theactuation rod (114) may be retracted until the indentations (130) of theactuation rod (114) reach the internal projections (128) of the lockingsheath (116). The expandable distal portion (126) of the locking sheath(116) may be biased toward an unexpanded state such that the internalprojections (128) reposition themselves into their respectiveindentations (130), as shown in FIG. 2D. The actuation rod (114) maythen be withdrawn to withdraw the locking sheath (116) (e.g., by virtueof the connection between the indentations (130) and the internalprojections (128)).

The grasper (200) may be configured to be actuated in any suitablemanner. In some variations, the grasper (200) may be configured suchthat it may be actuated by a force applied internally of the grasper(200) (e.g., via an actuation rod (114) of the delivery device (100)advanced through the lumen (212) of the barrel portion (210) of thegrasper (200), as discussed in more detail below), and may be furtherconfigured such that it may be actuated by a force applied externally ofa grasper (200) (e.g., via a grasping device). For example, in thevariation of the grasper (200) shown in FIGS. 2A-2F, the grasper (200)may comprise a proximal arm (220) connected to the first jaw (202),wherein rotation of the proximal arm (220) rotates the first jaw (202)relative to the main body (206) and second jaw (204) of the grasper(200). The proximal arm (220) may act as a lever and/or a cam to rotatethe first jaw (202).

For example, in some instances the proximal arm (220) may act as a camto rotate the first jaw (202). In these instances, the actuation rod(114) of the delivery device (100) may rotate the first jaw (202).Specifically, a portion of the proximal arm (220) may be alignedrelative to the lumen (212) such that advancement of the actuation rod(114) through the lumen (212) pushes the actuation rod (114) intocontact with the proximal arm (220), as illustrated in FIG. 2E. Once incontact with the proximal arm (220), advancement of the actuation rod(114) may push against the proximal arm (220). The proximal arm (220)may act as a cam to convert the linear motion of the actuation rod (114)into rotation of the proximal arm (220), which may in turn rotate thefirst jaw (202) away from the second jaw (204) as shown in FIG. 2F. Whenthe first jaw (202) is spring-biased toward the second jaw (204), therotation of the proximal arm (220) may overcome this spring bias, whichmay allow the actuation rod (114) to hold the first jaw (202) in itsopen position. Additionally, the first jaw (202) may rotate back towardthe second jaw (204) when the actuation rod (114) is retracted.

Additionally, in the variation of the grasper (200) shown in FIGS.2A-2F, at least a portion of the proximal arm (220) may be exposedrelative to the main body (206), which may allow a grasping device tograsp the proximal arm (220) to rotate the first jaw (202) relative tothe second jaw (204). For example, opposing forces (represented byarrows (222) in FIG. 2A) may be applied (e.g., via a grasping device) tothe exposed portion of the proximal arm (220) and the main body (206) tocause the proximal arm (220) to rotate around the pivot point (208)(which may in turn rotate the first jaw (202) away from the second jaw(204)).

While the proximal arm (220) is shown in FIGS. 2A-2F as being curved, itshould be appreciated that in some variations the graspers describedhere may comprise also comprise one or more straight segments. Forexample, FIGS. 3A and 3B depict cross-sectional side views of one suchvariation of a grasper (300) which may be used with the systemsdescribed here. As shown there, the grasper (300) may comprise a firstjaw (302), a second jaw (304), and a main body (306). The first jaw(302) may be rotatably coupled to the main body (306) at a pivot point(308), and the main body (306) of the grasper (300) may comprise abarrel portion (310) having a lumen (312) extending therethrough. Insome variations, the lumen (312) may comprise a proximal segment (314),a distal segment (316), and an intermediate segment (318), which may beconfigured as described above with respect to the variation of thegrasper (200) depicted in FIGS. 2A-2F.

As shown in FIGS. 3A and 3B, the grasper (300) may comprise a proximalarm (320) connected to or otherwise extending from the first jaw (302)such that rotation of the proximal arm (320) around the pivot point(308) also rotates the first jaw (302) around the pivot point. In thisvariation, the proximal arm (320) may comprise a straight segment (322)and a curved segment (324), and the proximal arm (320) may act as a camand/or lever to rotate the first jaw (302). Specifically, the straightsegment (322) may be positioned between the curved segment (324) and thefirst jaw (302), and may provide a flat surface which may facilitateengagement of the proximal arm (320) by a grasping device. For example,as shown in FIGS. 3A and 3B, at least a portion of the straight segment(322) may be exposed from the main body (306). Some or all of the curvedsegment (324) may also be exposed, although in some variations, thecurved segment (324) may be at least partially positioned within achannel (326) in the barrel portion (310) of the grasper (300). Opposingforces (represented in FIG. 3A by arrows (328)) may be applied (e.g.,via a grasping device) to an exposed portion of the straight segment(322) (and/or an exposed portion of the curved segment (324), when atleast a portion of the curved segment (324) is exposed) and the mainbody (306), which may cause the proximal arm (320) to act as a lever torotate around the pivot point (308). This in turn may rotate the firstjaw (302) away from the second jaw (304), as illustrated in FIG. 3B.When the first jaw (302) is configured to be rotatably biased toward thesecond jaw (304) (e.g., via one or more springs, as described in moredetail above), and the forces (328) holding the first jaw (302) rotatedaway from the second jaw (304) are removed from the proximal arm (320)and the main body (306), the first jaw (302) may rotate back toward thesecond jaw (304), as illustrated in FIG. 3A. When tissue is positionedbetween the first jaw (302) and the second jaw (304), this may connectthe grasper (300) to the tissue as discussed in more detail above.

Additionally, a delivery device (such as the delivery device (100)described above with respect to FIGS. 1A-1C and 2A-2F) may be configuredto actuate the jaws of the grasper (300) through the barrel portion(310), as illustrated in FIGS. 3A and 3B. The distal engagement portion(108) of the delivery device (100) may engage the barrel portion (310)of the grasper (300) (as discussed in more detail above), and theactuation rod (114) may be advanced through the lumen (312) of thebarrel portion (310) until the actuation rod (114) contacts the curvedsegment (324) of the proximal arm (320), such as shown in FIG. 3A. Insome instances, advancing the actuation rod (114) to this point maycause a locking sheath (116) of the delivery device (100) to couple tothe lumen (312) of the barrel portion (310) of the grasper (300), suchas described in more detail above. Further advancement of the actuationrod (114) may push the actuation rod (114) against the curved segment(324) of the proximal arm (320), and the proximal arm (320) may act as acam to convert the linear movement of the actuation rod (114) intorotational movement of the proximal arm (320). As the actuation rod(114) rotates the proximal arm (320), the first jaw (302) may rotateaway from the second jaw (304), as depicted in FIG. 3B. When theactuation rod (114) is withdrawn, the first jaw (302) may be biased torotate toward the second jaw (304) to return the first jaw (302) towardthe second jaw (304). Accordingly, the actuation rod (114) may beadvanced and withdrawn to cause the first jaw (302) to rotate away fromand toward, respectively, the second jaw (304). Additionally,positioning the straight segment (322) between the curved segment (324)and the pivot point (308) may create a longer moment arm, which mayreduce the force that must be applied to the curved segment (324) by theactuation rod (104) in order to rotate the first jaw (302). While theproximal arm (320) shown in FIGS. 3A and 3B is configured such that aconcave portion of the curved segment (324) faces the lumen (312) suchthat the actuation rod (114) contacts the concave portion of the curvedsegment (324) during advancement of the actuation rod (114), the curvedsegment may instead be configured such that a convex portion of a curvedsegment faces the lumen such that the actuation rod (114) contacts theconvex portion of the curved segment during advancement of the actuationrod (114).

While the variations of the graspers depicted in FIGS. 2A-2F and 3A-3Beach comprise a proximal arm that is configured to be used as both a camand a lever to actuate the grasper, in some variations the grasper maycomprise a first mechanism which may act as a cam to actuate the grasperand a second mechanism which may act as a lever to actuate the grasper.For example, FIGS. 4A and 4B depict one such variation of a grasper(400) suitable for use with the systems described here. As shown there,the grasper (400) may comprise a first jaw (402), a second jaw (404),and a main body (406). The first jaw (402) may be rotatably coupled tothe main body (406) at a pivot point (408), and the main body (406) ofthe grasper (400) may comprise a barrel portion (410) having a lumen(412) extending therethrough. In some variations, the lumen (412) maycomprise a proximal segment (414), a distal segment (416), and anintermediate portion (418), which may be configured as described abovewith respect to the variation of the grasper (200) depicted in FIGS.2A-2F.

Also shown in FIGS. 4A and 4B are a proximal arm (420) and an eccentriccam member (422). Each of the proximal arm (420) and the eccentric cammember (422) may be attached to the first jaw (402), such that rotationof either the proximal arm (420) or the eccentric cam member (422)relative to the pivot point (408) may rotate the first jaw (402). Forexample, opposing forces (represented by arrows (428)) may be applied tothe main body (406) and the proximal arm (420), which may rotate theproximal arm (420) relative to the main body (406) and act as a lever torotate the first jaw (402) away from the second jaw (404), such as shownin FIG. 4B. In some variations, the first jaw (402) may be rotatablybiased toward the second jaw (404) (e.g., via one or more springs, asdescribed in more detail above), such that when the forces (428) areremoved from the proximal arm (420) and/or main body (406), the firstjaw (402) may rotate back toward the second jaw (404), as illustrated inFIG. 4A.

Similarly, the eccentric cam member (422) may be rotated via a portionof a delivery device that may be advanced through the lumen (412) of thebarrel portion (410) of the grasper (400). In some instances, thedelivery device (100) described above may actuate the grasper (400). Thedistal engagement portion (108) of the delivery device (100) may engagethe barrel portion (410) of the grasper (400) (as discussed in moredetail above), and the actuation rod (114) may be advanced through thelumen (412) of the barrel portion (410) until the actuation rod (114)contacts the eccentric cam member (422) (which may be aligned with thelumen (412)), such as shown in FIG. 4A. In some instances, advancing theactuation rod (114) to this point may cause a locking sheath (116) ofthe delivery device (100) to couple to the lumen (412) of the barrelportion (410) of the grasper (400), such as described in more detailabove. Further advancement of the actuation rod (114) may push againstthe eccentric cam member (422), which may convert the linear movement ofthe actuation rod (114) into rotational movement of the eccentric cammember (422). As the actuation rod (114) rotates the eccentric cammember (422), the first jaw (402) may rotate away from the second jaw(404), as depicted in FIG. 4B. When the actuation rod (114) iswithdrawn, the first jaw (402) may be biased to rotate back toward thesecond jaw (404). Accordingly, the actuation rod (114) may be advancedand withdrawn to cause the first jaw (402) to rotate away from andtoward, respectively, the second jaw (404).

Returning to FIGS. 2E-2F, the actuation rod (114) may be advanced andwithdrawn in any suitable manner. For example, when the delivery device(100) comprises an actuation control mechanism, such as a slider, knob,trigger, or the like, the actuation control mechanism may be operativelyconnected to the actuation rod (114) such that the actuation controlmechanism may advance and withdraw the actuation rod (114). For example,in the variation of the delivery device (100) shown in FIGS. 1A-1C, thetrigger (112) may be configured to advance and retract the actuation rod(114). In some of these variations, the trigger (112) may be configuredsuch that rotation of the trigger (112) toward the grip portion (110)withdraws the actuation rod (114) relative to the shaft (106), whilerotation of the trigger away from the grip portion (110) advances theactuation rod (105) relative to the shaft. In these variations, when thetrigger (110) is in the first position (as shown in FIG. 1A), theactuation rod (114) may be positioned as shown in FIGS. 2A and 2B withthe coupling magnet (118) in an advanced position, which may allow thedistal engagement portion (108) to connect to a grasper (such as grasper(200), as illustrated in FIGS. 1A and 2B). The trigger (112) may berotated toward the grip portion (110) to position the trigger (112) inthe third position (as shown in FIG. 1C), and this rotation may retractthe actuation rod (114) relative to the shaft (106). Retraction of theactuation rod (114) may also withdraw the coupling magnet (118) to aretracted position, such as illustrated in FIG. 2C, which may decouple agrasper from the delivery device (100) as described above. The trigger(112) may be rotated away from the grip portion (110) and back to thefirst position to advance the actuation rod (114) back to the positionshown in FIGS. 2A and 2B. Further rotation of the trigger (112) awayfrom the grip portion (110) may move the trigger (112) from the firstposition to the second position (as shown in FIG. 1B) and may advancethe actuation rod (114) through a lumen of a barrel portion of a grasper(e.g., the lumen (212) of the barrel portion (210) of the grasper (200)described above) to rotate one or more jaws of the grasper (as shown inFIG. 2F). Returning the trigger (112) to the first position (e.g., byrotating the trigger (112) toward the grip portion (110)) may withdrawthe actuation rod (114) relative to the shaft (106) and the grasper,which may allow the grasper to return to a closed configuration. Itshould be appreciated that in some variations, rotation of the trigger(112) toward the grip portion (110) may be configured to advance theactuation rod (114) relative to the shaft (106), while rotation of thetrigger (112) away from the grip portion (110) may retract the actuationrod (114) relative to the shaft (106).

FIGS. 6A-6C depict another variation of a grasper (600) as describedhere. Specifically, FIGS. 6A and 6B show perspective and side views,respectively, of the grasper (600). As shown there, the grasper (600)may comprise a first jaw (602), a second jaw (604), and a main body(606). Generally, the first jaw (602) may be rotatably connected to themain body (606) at a pivot point (608), such that the first jaw (602)may rotate relative to the main body (606). While the second jaw (604)is shown in FIGS. 6A-6C as being fixed relative to the main body (606),it should be appreciated that in some variations the second jaw (604)may be rotatably connected to the main body (606), such as discussed inmore detail above. The first jaw (602) (and/or the second jaw (604) invariations where the second jaw (604) is rotatably connected to the mainbody (606)) may be rotated relative to the main body (606) to actuatethe grasper (600) between an open configuration and a closedconfiguration. Specifically, in the open configuration, the first jaw(602) and the second jaw (604) may be held in rotationally separatedpositions to define a space between the first jaw (602) and the secondjaw (604), as shown in FIG. 6A. In the closed configuration, the firstjaw (602) and second jaw (604) may be rotationally biased toward eachother, as shown in FIG. 6B. While the first jaw (602) is shown ascontacting the second jaw (604) in FIG. 6B, it should be appreciatedthat when the grasper (600) is connected to tissue, tissue positionedbetween the first jaw (602) and the second jaw (604) may prevent thefirst jaw (602) from contacting the second jaw (604) when the grasper isin the closed configuration. The first jaw (602) and second jaw (604)may be rotationally biased toward a closed configuration in any suitablemanner (e.g., via a torsional spring (not shown)), such as described inmore detail above.

The main body (606) of the grasper (600) may comprise a barrel portion(610) with a lumen (612) extending therethrough. A portion of a deliverydevice may be advanced at least partially into the lumen (612) toactuate the grasper (600) between closed and an open configurations, aswill be discussed in more detail below. The outer diameter of the barrelportion (610) may be uniform, or may vary along the length of the barrelportion (610). For example, in the variation of the grasper (600) shownin FIGS. 6A-6C, the barrel portion (610) may have a first segment (640)having a first outer diameter and a second segment (642) having a secondouter diameter. In some variations, the second outer diameter may begreater than the first outer diameter, which may allow the secondsegment (642) to act as a stop when engaged by a delivery device, suchas will be discussed in more detail above. For example, in somevariations the first segment may have a first outer diameter of about 10mm, and the second segment may have an outer diameter between about 7 mmand about 9 mm.

In some variations (such as the variation of grasper (600) illustratedin FIGS. 6A-6C), the barrel portion (610) may further comprise a taperedportion (644) positioned between the first segment (640) and the secondsegment (642), such that the outer diameter of the tapered segment (644)tapers between the first outer diameter and the second outer diameter.It should be appreciated, however, that the barrel portion (610) neednot have such a tapered portion (644), and the first segment (640) mayimmediately transition to the second segment (642). In variations thatdo include a tapered segment (644), the tapered segment (644) mayprovide a gradual diameter transition between the first (640) and second(642) segments, which may in turn reduce the presence of edges that maycatch on or otherwise disturb tissue during use of the grasper (600).

Additionally or alternatively, the barrel portion (610) may have atapered segment (646) at a proximal end of the barrel portion (610),which may also be at a proximal end of the first segment (640). In thesevariations, the diameter of the tapered segment (646) may taper from thefirst outer diameter of the first segment (640) to a third outerdiameter smaller than that of the first outer diameter. In variationsthat include a tapered segment (646) at a proximal end of the barrelportion (610), the tapered diameter may facilitate alignment of thebarrel portion (610) with a portion of the delivery device.Specifically, when a proximal end of the barrel portion (610) isinserted into a portion of a delivery device (as described in moredetail below), the tapered segment (646) may help guide the barrelportion (610) into the delivery device, which may be beneficial ininstances where the delivery device (or another retrieval device) isconnected to the grasper to retrieve the grasper.

The first jaw (602) may be configured to rotate in any suitable mannersuch as described above. For example, in the variation of the grasper(600) shown in FIGS. 6A-6C, the grasper (600) may comprise a proximalarm (620) connected to the first jaw (602) such that rotation of theproximal arm (620) relative to the pivot point (608) rotates the firstjaw (602) relative to the pivot point (608) (which may also rotate thefirst jaw (602) relative to the main body (606) and/or the second jaw(604)). While the proximal arm (620) shown in FIGS. 6A-6C may comprise acurved arm (620) that may be configured to act as both a cam and a lever(similar to the proximal arm (220) of the grasper (200) discussed abovewith respect to FIGS. 1A-1C and 2A-2F), it should be appreciated thatthe grasper may include any of the proximal arms and/or eccentric cammembers discussed above with respect to FIGS. 3A-3B and 4A-4B. Theproximal arm (620) (and/or an eccentric cam member) may assist inactuation of the grasper (600), as described hereinthroughout.

Generally, at least a portion of the proximal arm (620) may be exposedrelative to the main body (606), which may allow a grasping device tograsp the proximal arm (620) to rotate the first jaw (602) relative tothe second jaw (604), as will be discussed in more detail below.Specifically, the main body (606) may comprise a barrel extension (660)between the barrel portion (610) and the pivot point (608). As shown ina cross-sectional side view in FIG. 6C, the barrel extension (660) maycomprise a channel (662) extending at least partially through the barrelextension (660). In the variation shown in FIGS. 6A-6C, the channel(662) may extend entirely through the barrel extension (660). The barrelextension (660) may have a wall (664) on one or both sides of thechannel (662). In the variation shown in FIGS. 6A-6C, the barrelextension (660) may have a wall (664) on each side of the channel (662).The proximal arm (620) may be positioned at least partially within thechannel (662), and may be configured to rotate through the channel (662)as the grasper (600) is actuated between open and closed configurations.

Generally, each wall (664) of the barrel extension (660) may have a topedge (666) and a bottom edge (668). The top edge (666) and bottom edge(668) may have any suitable profile, and together may define a height ofthe wall (664). For example, in the variation shown in FIGS. 6A-6C, thebottom edge (668) may be linear and substantially parallel to alongitudinal axis, while the top edge (666) may include a linear portion(680) positioned between two ramped segments (labeled (682) and (684)).In these variations, the height of the walls (664) may decrease alongeach of the ramped segments (682) and (684) toward the linear portion(680). This may facilitate grasping of the grasper (600) with a graspingdevice, as will be described in more detail below. In other variations,the top edge (666) and/or the bottom edge (668) may have a curvedprofile.

In some variations, the graspers described here may comprise a shuttlepin at least partially positioned in a lumen of the barrel portion ofthe grasper. Generally, the shuttle pin may reduce the distance anactuation rod may need to be inserted into the barrel portion in orderto actuate the grasper. For example, in the variation of the grasper(600) shown in FIG. 6C, the grasper (600) may further comprise a shuttlepin (650). The shuttle pin (650) may be positioned at least partiallywithin the lumen (612) of the barrel portion (610) of the grasper (600)and may be configured to slide relative to the lumen (612). The shuttlepin (650) may have a proximal end (652) and a distal end (654), and mayassist in actuation of the grasper (600). Specifically, advancement of aportion of a delivery device (e.g., an actuation rod) into the lumen(612) of the barrel portion (610) may cause the delivery device tocontact the proximal end (652) of the shuttle pin (650) and advance theshuttle pin (650) relative to the lumen (612). As the shuttle pin (650)is advanced relative to the lumen (612) of the barrel portion (610), thedistal end (654) of the shuttle pin (650) may press against the proximalarm (620) (or an eccentric cam member, in variations where the grasperincludes an eccentric cam member), which may cause the proximal arm(620) to act as a cam member, such as discussed in more detail above.Without the shuttle pin (650), an actuation rod may otherwise need to beinserted into the barrel portion (610) until it contacts the proximalarm (620) directly, such as discussed above. When the delivery device iswithdrawn relative to the shuttle pin (650), the return bias of thefirst jaw (202) toward a closed configuration may push the shuttle pin(650) proximally relative to the lumen (612) of the barrel portion(610). While the variations of the graspers discussed above with respectto FIGS. 2A-2F, 3A, 3B, 4A, and 4B are not depicted as having a shuttlepin, it should be appreciated that any of these graspers may comprise ashuttle pin, which may be configured in any suitable manner as discussedwith respect to shuttle pin (650) of the grasper (600) shown in FIGS.6A-6C.

In variations where the graspers described here comprise a shuttle pin,the grasper may be configured to help prevent the shuttle pin fromdisengaging from the grasper. In some variations, at least a portion ofa shuttle pin may be configured to have an outer profile that is largerthan at least a portion of the lumen of the barrel portion of a mainbody. For example, in the variation of the shuttle pin (650) shown inFIG. 6C, the distal end (654) may comprise a cap (656) that may have anouter diameter sized to be larger than the lumen (612) of the barrelportion (610) of the main body (606). The shuttle pin (650) may bepositioned in the lumen (612) such that the cap (656) is positioneddistally of the lumen (612). Because the cap (656) is sized larger thanthe lumen (612), it may be prevented from entering the lumen (612) asthe shuttle pin (650) is slid proximally relative to the barrel portion(610). Accordingly, the shuttle pin (650) may slide proximally until thecap (656) contacts the barrel portion (610), at which point the cap(656) may act as a stop to prevent further proximal movement of theshuttle pin (650). This may prevent the shuttle pin (650) from slidingout of the proximal end of the barrel portion (610) and disengaging thegrasper (600).

Additionally, the grasper (600) may be configured to limit the amount ofdistal advancement of the shuttle pin (650). Generally, a portion of aproximal arm or an eccentric cam member (e.g., the proximal arm (620) ofgrasper (600)) may be aligned with the lumen of the barrel portion,which may resist or stop forward advancement of the shuttle pin (650)due to gravitational forces. When a delivery device or other device isused to advance the shuttle pin (650) to rotate the proximal arm and/oreccentric cam member, the delivery device and/or grasper may beconfigured to limit advancement of the shuttle pin (e.g., by blockingadvancement of the shuttle pin (650) when the grasper is opened, asdiscussed in more detail below). In some of these variations, when adelivery device is used to advance the shuttle pin (650), it may beconfigured to advance the shuttle pin a predetermined distance (e.g.,about 1 cm, about 1.25 cm, about 2 cm, or the like)) to actuate thegrasper (600). In these variations, the shuttle pin (650) may be sizedto be longer than this predetermined distance (e.g., greater than about2.5 cm, greater than about 3 cm, or the like), such that a least aportion of the shuttle pin (650) may remain in the lumen when fullyadvanced by the delivery device. In some of these variations, theshuttle pin may be sized with a length such that at least apredetermined length (e.g., about 1.25 cm) of the shuttle pin remains inthe lumen (612) when the shuttle pin (650) has been advanced thepredetermined distance (e.g., for an advancement distance of about 1.25cm, the shuttle pin may have a length of about 2.5 cm). Additionally oralternatively, the grasper (600) may be configured to limit the amountthat the delivery device may advance the shuttle pin (650). For example,in some variations, a portion of the grasper (600) may be positioned inthe path of the shuttle pin (650) and resists further advancement of theshuttle pin (650) by the delivery device. For example, the pivot point(608) may be positioned along the movement path of the shuttle pin(650). In these variations, the distal end (654) of the shuttle pin(650) may be stopped from further advancement by a portion of the firstjaw (602) and/or the proximal arm (620) (and/or the eccentric cammember, in variations where the grasper contains an eccentric cammember) near the pivot point (608).

The grasper (600) shown in FIGS. 6A-6C may be actuated in any suitablemanner. In some variations, the grasper (600) may be configured suchthat it may be actuated by a force applied internally of the grasper(600) (e.g., via an actuation rod of a delivery device advanced throughthe lumen (612) of the barrel portion (610) of the grasper (600), asdiscussed in more detail below), and may be further configured such thatit may be actuated by a force applied externally of a grasper (600)(e.g., via a grasping device). FIGS. 7A-7D depict cross-sectional sideviews of a distal portion of a delivery device (700) and a manner ofactuating the grasper (600) using the delivery device (700). Thedelivery device (700) and grasper (600) may be configured forlaparoscopic introduction into the body, such as described above.Specifically, the delivery device (700) may comprise a handle (notshown), a shaft (706) extending from the handle, and a distal engagementportion (708) at a distal end of the shaft (706). The handle maycomprise an actuation control mechanism that may be manipulated by auser to controllably actuate the grasper, and may be configured asdescribed above with respect to the handle (104) of the delivery device(100) described above with respect to FIGS. 1A-1C. In some of thesevariations, the actuation control mechanism may comprise a trigger.

In some of these variations, the actuation control mechanism may beconfigured to both actuate the grasper (600) and the delivery device(700). In variations where the actuation control mechanism comprises atrigger, the trigger may be moveable between three positions (althoughit should be appreciated that the trigger may assume one or moreintermediate positions between these positions). Of the three positions,the trigger may be moveable between a first position (such as theposition of the trigger (112) of the delivery device (100) shown in FIG.1A) and a second position (such as the position of the trigger (112) ofthe delivery device (100) as shown in FIG. 1B) to close and open,respectively, the grasper (600). The trigger may be moveable to a thirdposition (such as the position of the trigger (112) of the deliverydevice (100) as shown in FIG. 1C) to eject or otherwise release thegrasper (600) from the delivery device (700). In some of thesevariations, to move the trigger from the second position (in which thegrasper (600) is placed in an open configuration) to the third position(to eject the grasper (600) from the delivery device (700)), the triggermay need to be moved through the first position, thereby moving thegrasper (600) to a closed configuration prior to ejecting the grasper(600).

Returning to FIGS. 7A-7D, in some variations the distal engagementportion (708) of the delivery device (700) may comprise a couplingmagnet (718) and a spring (720). In these variations, the couplingmagnet (718) may be slidably housed in the distal engagement portion(708) (e.g., in a housing of the distal engagement portion (708)). Thecoupling magnet (718) may be moveable between an advanced position (asdepicted in FIG. 7A-7C) and a retracted position (as depicted in FIG.7D). The spring (720) may be positioned within the distal engagementportion (708) such that the spring (720) biases the coupling magnet(718) toward the advanced position. The delivery device (700) may beconfigured to couple to the grasper (600) when the coupling magnet (718)is in the advanced position. As mentioned above, at least a portion ofthe grasper (600) may be formed from one or more metallic or magneticmaterials. When the grasper (600) is positioned near the distalengagement portion (708) (such as shown in FIG. 7A), the coupling magnet(718) attract the grasper (600) and temporarily couple the grasper (600)to the delivery device (700).

Specifically, when the grasper (600) is temporarily coupled to thedelivery device (700), at least a portion of the barrel portion (610)may be positioned within the distal engagement portion (708), as shownin FIG. 7B. The attractive force between the coupling magnet (718) andthe grasper (600) may hold the grasper (600) in place. In variationswhere the grasper (600) has a barrel portion (610) having a firstsegment (640) having a first outer diameter and a second segment (642)having a second outer diameter, the first outer diameter may be sized tofit within the distal engagement portion (708) while the second outerdiameter may be sized such that it is too large to fit within the distalengagement portion (708). In these variations, the second segment (642)(or a tapered segment (644) between the first segment (640) and thesecond segment (642)) may act as a stop to limit the amount of thebarrel portion (610) that may enter the distal engagement portion (708).

To decouple the grasper (600) from the distal engagement portion (708),the coupling magnet (718) may be withdrawn to the retracted position,such as shown in FIG. 7D. As the coupling magnet (718) is retracted, theattractive force between the coupling magnet (718) and the grasper (600)may pull the grasper (600) proximally relative to the distal engagementportion (708). The second segment (642) (or the tapered segment (644))may limit the withdrawal of the grasper (600), such that the distancebetween the coupling magnet (718) and the grasper (600) increases. Thismay decrease the attractive force between the coupling magnet (718) andthe grasper (600), which may allow the grasper (600) to be pulled from,released from, or otherwise fall from the distal engagement portion(708).

The coupling magnet (718) may be retracted in any suitable manner, suchas described in more detail above. For example, in the variation of thedelivery device (700) shown in FIGS. 7A-7D, the delivery device (700)may comprise an actuation rod (714) slidably disposed in the shaft(706). The actuation rod (714) may be configured to retract the couplingmagnet (718). For example, the actuation rod (714) may be slidablydisposed within a lumen (722) of the coupling magnet (718). In somevariations, at least a segment of the actuation rod (714) may be sizedand configured such that the portion of the actuation rod (714) cannotfully pass through the lumen (722). For example, the variation shown inFIG. 7A-7D a segment (740) of the actuation rod may have a diametergreater than a diameter of the lumen (722). Additionally oralternatively, the segment (740) may comprise one or more projectionsextending from an outer surface of the actuation rod (714) and whichcannot fully pass through the lumen (722). When the segment (740) of theactuation rod (714) is positioned distal to the coupling magnet (718),the actuation rod (714) may be freely advanced relative to the couplingmagnet (718). Conversely, withdrawal of the actuation rod (714) may pullthe segment (740) of the actuation rod (714) into contact with thecoupling magnet (718). Since the segment (740) cannot fully pass throughthe lumen (722) of the coupling magnet (718), further withdrawal of theactuation rod (714) may cause the segment of the actuation rod (714) topull on and withdraw the coupling magnet (718). When the actuation rod(714) is subsequently advanced, the spring (720) may advance thecoupling magnet (718) with the actuation rod (714) until the couplingmagnet (718) reaches the advanced position.

The actuation rod (714) may be advanced or retracted relative to theshaft (706) to actuate and/or eject the grasper (600). In variationswhere the handle comprises a trigger (such as discussed above), thetrigger may be operatively connected to the actuation rod (714), suchthat movement of the trigger slides the actuation rod (714). Movement ofthe actuation rod (714) may rotate the first jaw (602) of the grasper(600). Specifically, when the grasper (600) is coupled to the deliverydevice (700) (as shown in FIG. 7B), the actuation rod (714) may bealigned with the lumen (612) of the barrel portion (610) such that theactuation rod (714) enters the lumen (612). As the actuation rod (714)is advanced into the lumen (612), the actuation rod (714) may pressagainst the proximal end (652) of the shuttle pin (650) and advance theshuttle pin (650) along the lumen (612). As the shuttle pin (650) isadvanced along the lumen (612), the distal end (654) of the shuttle pin(650) may move into the channel (662) of the barrel extension (660). Thedistal end of the shuttle pin (650) may in turn push against theproximal arm (620) (e.g., against a portion of the proximal arm (620)that is positioned in the channel (662) and aligned with the lumen(612)). The proximal arm (620) may act as a cam to convert the linearmotion of the shuttle pin (650) into rotation of the proximal arm (620),which may in turn rotate the first jaw (602) away from the second jaw(604). When the first jaw (602) is spring-biased toward the second jaw(604), the rotation of the proximal arm (620) may overcome this springbias, which may allow the actuation rod (714) to hold the first jaw(602) in its open position, as shown in FIG. 7C.

Additionally, the first jaw (602) may rotate back toward the second jaw(604) when the actuation rod (714) is retracted. Specifically, as theactuation rod (714) is withdrawn, the return bias of the first jaw (602)may cause the proximal arm (620) to push against the shuttle pin (650),which may slide the shuttle pin (650) proximally within the lumen (612).This may return the grasper to a closed configuration, such as shown inFIG. 7B. When the grasper (600) is closed around tissue, the actuationrod (714) may be further retracted to release the grasper (600) from thedelivery device (700), as discussed above. When a trigger is moveablebetween three positions to actuate and release the grasper (600) asdiscussed above, placing the trigger in the first position may positionthe actuation rod (714) in a position as illustrated in FIG. 7B, inwhich the grasper (600) may be coupled to the delivery device (700) in aclosed configuration. Moving the trigger to the second position mayadvance the actuation rod to the position illustrated in FIG. 7C, inwhich the grasper (600) may be releasably coupled to the delivery device(700) in an open configuration. Moving the trigger to the third positionmay retract the actuation rod (714) to the position illustrated in FIG.7D, in which the grasper (600) may be decoupled from the delivery device(700).

Additionally, in the variation of the grasper (600) shown in FIGS.6A-6A, at least a portion of the proximal arm (620) may be exposedrelative to the main body (606) (e.g., at least a portion of theproximal arm (620) may extend out of the channel (662) of the barrelextension (660)), which may allow a grasping device to grasp theproximal arm (620) to rotate the first jaw (602) relative to the secondjaw (604). For example, opposing forces (represented by arrows (622) inFIG. 6C) may be applied (e.g., via a grasping device) to the exposedportion of the proximal arm (620) and the main body (606) (e.g., thebarrel extension (660)) to cause the proximal arm (620) to rotate aroundthe pivot point (608) (which may, in turn rotate the first jaw (602)away from the second jaw (604)). In these variations, the height of thewalls (664) of the barrel extension (660) may limit the amount that theproximal arm (620) may be rotated (e.g., a grasping device may rotatethe proximal arm (620) until the grasping device contacts the top andbottom edges of the wall). Additionally, when top and/or bottom edges ofa wall of the barrel portion is curved or ramped, the curved or rampededges may help guide a grasping device toward another section of thebarrel extension (660) during grasping. Specifically, if the graspingdevice applies a compressive force at a ramped or curved portion of anedge, the grasping device may slide along the ramped/curved portiontoward a shorter portion of the wall. For example, in the variation ofthe grasper (600) shown in FIGS. 6A-6C, if a grasping device applies acompressive force at either the ramped segments (682) or (684) of thetop edge (666), the grasping device may slide toward the linear portion(680).

In some variations of the graspers described here, the grasper maycomprise one or more coatings which may help to smooth discontinuitiesin the contours of the grasper and may act to provide one or moreatraumatic surfaces of the grasper. The one or more coatings maycomprise silicone, urethane, one or more nylon blends, polyethylenes,fluoropolymers, combinations thereof and the like. Additionally, thejaws of the graspers described above may comprise one or more featureswhich may promote engagement with tissue. In some variations, one ormore surfaces of a jaw may be roughened, which help to reduce slippingbetween the jaws and tissues. Additionally or alternatively, thegraspers may comprise teeth or other projections which may facilitateengagement of the jaw with tissue.

In some variations, one or more jaws of the graspers described here mayinclude a longitudinal recess extending at least partially through thejaws. For example, in the variation of the grasper (600) shown in FIGS.6A-6C, the first jaw (602) and the second jaw (604) may each include agrasping surface (690) having a plurality of teeth (692), and mayinclude a recess (694) extending at least partially through the graspingsurface (690) and some of the teeth (692). In these variations, when thejaws are used to grasp tissue therebetween, tissue may be squeezed orcaptured into or otherwise enter the recess (694) of each jaw, which mayhelp to provide a more secure hold between the grasper (600) and thetissue.

As mentioned above, the graspers described here may be used to provideremote suspension of tissue during a minimally-invasive procedure.Generally, to provide suspension of a tissue, a grasper as describedherein may be advanced into the body, may be releasably connected to atissue in the body, and may be suspended using one or more magnetspositioned externally to the body to move and suspend the tissue. Insome variations, the connection between the grasper and the tissue maybe released, and the grasper may be repositioned and reconnected totissue (either the same tissue or different tissue).

The grasper may be advanced into the body in any suitable manner. Insome variations, the grasper may be advanced into the body through alaparoscopic port as part of a laparoscopic procedure. In someinstances, the laparoscopic procedure may be a reduced port technique orsingle-incision laparoscopic procedure. In some variations, the graspermay be advanced into the body using a delivery device, such as thedelivery device (100) described above with respect to FIGS. 1A-1C and2A-2F. In these variations, the grasper may be releasably coupled to adistal engagement portion of the delivery device, and the distalengagement portion of the delivery device may be advanced into the bodyto advance and position the grasper within the body.

Once the grasper is positioned in the body, it may be releasablyconnected to tissue. To connect the grasper to tissue, the grasper mayfirst be placed in an open configuration, in which a first jaw of thegrasper is rotated away from a second jaw of the grasper. In somevariations, the grasper may be placed in an open configuration using thedelivery device carrying the grasper (e.g., by advancing an actuationrod through a barrel portion of the grasper, such as described in moredetail above with respect to FIGS. 2A-2F) or by a grasping device whichmay engage and move the grasper to the open configuration (as describedin more detail above). With the grasper in the open configuration, thegrasper may be manipulated to position the tissue between the first jawand the second jaw. The grasper may be returned to a closedconfiguration, in which the first jaw rotates toward the second jaw tohold the tissue between the jaws. The grasper may then be released fromthe delivery device and/or grasping device, and these devices may beremoved from the body.

With the grasper releasably connected to the tissue, a magnetic controlelement comprising one or more magnets may be positioned externally ofthe body and may magnetically attract the grasper to reposition and/orhold the grasper. For example, FIGS. 5A-5D depict an illustrative methodby which a grasper may be used to reposition and/or hold tissue. Whilethe variations of the grasper (200) and the delivery device (100) thatare described above with respect to FIGS. 1A-1C and 2A-2F are depictedin FIGS. 5A-5D, it should be appreciated that any suitable graspersand/or delivery systems as described here may perform the stepsdiscussed below. Specifically, as shown in FIG. 5A, the grasper (200)may be advanced into the body toward a target tissue (502) (shown inFIG. 5 as a gallbladder, although it should be appreciated that thegraspers described here may be releasably connected to any suitabletissue), and positioned in an open configuration. To advance the grasper(200), the grasper (200) may be releasably coupled to a distalengagement portion (108) of a delivery device (100), and a user mayadvance the distal engagement portion (108) into the body to positionthe grasper (200). The tissue (502) may be positioned between the first(202) and second (204) jaws of the grasper (200), and the grasper (200)may be moved to a closed configuration to releasably couple the grasper(200) to the tissue (502), as shown in FIG. 5B. Once connected to thetissue (502), the grasper (200) may be released from the delivery device(100), and the delivery device may be removed from the body.

When a magnetic control device (500) is positioned externally of thebody, the magnetic control device (500) may attract the grasper (200)and lift the grasper toward the magnetic control device (500). When thegrasper (200) is placed in the abdomen, this may lift the grasper towarda wall (represented by line (504)) of the abdomen, such as shown in FIG.5C. The magnetic control device may be further manipulated to repositionthe grasper (200) and the tissue (502).

As mentioned above, in some instances it may be desirable to release theconnection between the grasper (200) and the tissue (502). For example,in some instances it may be desirable to connect the grasper to adifferent portion of the tissue. In these instances, the grasper may bereturned to an open configuration (either using one of the deliverydevices described here or a grasping device, as discussed above) torelease the grasper from the tissue. For example, FIG. 5D shows agrasping device (506) having opposing jaws (508) which may grab aproximal arm (220) and the main body (206) of the grasper (200) torotate the first jaw (202) away from the second jaw (204), which mayrelease the grasper (200) from tissue. The grasper may be repositionedto again place tissue between the jaws of the grasper, and the graspermay then be placed in the closed configuration to reconnect the grasperto tissue. In other instances, the grasper may be decoupled from thetissue, and removed from the body.

What is claimed is:
 1. A system for grasping tissue comprising: agrasper comprising a main body comprising a barrel portion having alumen extending therethrough, a first jaw rotatably coupled to the mainbody, a proximal arm connected to the first jaw, and a second jaw fixedrelative to the main body, wherein at least a portion of the proximalarm is exposed from the main body and the proximal arm comprises acurved portion, wherein the device is configured such that a forceapplied to the exposed portion of the proximal arm and the main bodyrotates the first jaw relative to the second jaw; and a delivery devicecomprising a handle, a distal engagement portion configured toreleasably couple to the grasper, a shaft connecting the handle and thedistal engagement portion, and an actuation rod, wherein advancement ofthe actuation rod through the lumen contacts the proximal arm to rotatethe proximal arm and the first jaw relative to the second jaw, whereinthe distal engagement portion comprises a coupling magnet configured toconnect the distal engagement portion to the grasper, and whereinretraction of the coupling magnet decouples the grasper from the distalengagement portion.
 2. The system of claim 1 wherein at least a portionof the grasper is formed from at least one magnetic or ferromagneticmaterial.
 3. The system of claim 1 wherein the proximal arm furthercomprises a straight segment positioned between the curved segment andthe first jaw.
 4. The system of claim 1 wherein the first jaw isrotationally biased toward the second jaw.
 5. The system of claim 1wherein retraction of the actuation rod is configured to retract thecoupling magnet.
 6. The system of claim 1 wherein the distal engagementportion comprises a spring positioned to bias the coupling magnet towardan advanced position.
 7. The system of claim 1 wherein the handlecomprises a trigger, and wherein the movement of the trigger isconfigured to actuate the grasper and to decouple the grasper from thedelivery device.